2 Chainz upped the star power at South by Southwest during his set at SOBs 30th Anniversary event at The Belmont in Austin, Texas, on Wednesday. Concertgoers whipped out their camera phones when Kanye West and Big Sean hit the stage with their Def Jam labelmate. They performed “Marvin & Chardonnay” and Yeezy had the audience singing along to “Can’t Tell Me Nothing.” Watch the G.O.O.D. Music crew’s surprise performance.